WA-1 carb

54coupe

Can anyone tell me the CFM rating, and your source of information, for a 2009s Carter WA-1 carburetor? I'm trying to help a non Hudson guy in a foreign country who wants to use them in multiples.

Glowplug

There is a very good description on how to determine CFM at this URL
http://www.nationalrestorationparts.com/engine/how-to-determine-correct-carb-cfm/

This a real ball park formula. For a more accurate calculation, see the Carburetor Sizing Calculator. But, this is still a good formula for general sizing purposes.
d = Displacement in Cubic Inches. (d x 2) – 15% = CFM
EXAMPLE: d = 350 (350 X 2) = 700 (700 – 15%) = 595 CFM

Also SUMMIT Racing has several pages of detailed information on CFM and VE measurememts

https://help.summitracing.com/app/answers/detail/a_id/4767/~/carburetor-cfm-rating

If you want a more personalized cfm rating, you can calculate the number yourself. You will need to know your engine's:

• Volumetric Efficiency (VE),
• Displacement (in c.i.d.), and
• Maximum rpm.

The formula is:

cfm = (c.i.d. x rpm x VE) / 3,456

https://help.summitracing.com/app/answers/detail/a_id/4741/related/1/session/L2F2LzEvdGltZS8xNTgzODE1ODAwL2dlbi8xNTgzODE1ODAwL3NpZC9mVThvSVdnd01lTjlLQWNCbEhiRTZFb2ZyazVWSnVacUJtV1JUZkp3RmJNJTdFVnduTHNObUJpOWZQMWV1JTdFM084T1lPdVJFRE1Ic2dQdElUTFdWekRiMzVUM3d6U2tXcyU3RSU3RU5yaGRVcFBCdWVseExZMHVMUWJyaWh3QSUyMSUyMQ%3D%3D

Volumetric efficiency (VE) is the actual amount of air flowing through an engine, compared to its theoretical maximum. Basically, it is a measure of how full the cylinders are.

VE is expressed as a percentage. An engine operating at 100% VE is using all of its volumetric capacity.

How is it calculated?

The formula for VE is:

VE = (cfm x 3,456) / (c.i.d. x rpm)

The specific CFM capability for a WA1 carburator is NOT listed in the Carter manual for this carburetor. It maybe possible to calculate the CFM from the mechanical size of the carburetors bore?    

Dimensions: Flange size, 1'14 inch S. A. E. Primary venturi, 11/32 inch I. D. Secondary venturi, 11/16 inch I. D. Main venturi, I% inch I. D.

charles4d

150 cfm according to  Daytona  Carburetor. 386-427-7108 said that carb is on a Jet
Hope this helps

54coupe

Thank you Charles. I will pass that along.

54coupe

Glowplug thank you for that information. I can use it for other builds as well.